The present invention is directed, in general, to electronic circuits and, more specifically, to a voltage reference translation system, a method of converting signals and an electronic circuit employing the voltage reference translation system and the method.
In general, the demand for smaller electronic circuit modules having more features or capabilities than their predecessors has been increasing. This is especially true in the case of power converter circuits that may be associated with either computer or telecommunications equipment. DC-DC converters employed in these applications may be designed for lower output voltages, such as 3.3 volts or less, with the need for high conversion density and efficiency, as well.
An output filter associated with such applications often includes inductors that employ the use of a common magnetic core, such as an E-core coupled to both inductors. The common magnetic device may be clamped around planar windings in a printed wiring board or employ conductive wires that are independent of the printed wiring board to form such inductors. Since higher power capabilities often dictate large current requirements, particularly in the case of lower voltage converters, wiring resistance typically has a significant impact on overall conversion efficiency.
Layout of the printed wiring board, in these cases, often dictates that the inductors be formed in such a way that coupled inductance is inserted in both legs of a circuit that is then coupled to an output of the power converter. Although this results in an efficient layout from a power conversion perspective, the output of the power converter is now separated from rectifying diodes located at the input of the power converter and no longer shares a common reference node or grounding point.
From an operational perspective, it is often required to reference an active circuit (such as an operational amplifier and its associated bias voltage) that is used to sense an output voltage to the reference node associated with the rectifying diodes. However, with the arrangement of an inductance inserted in both legs of a circuit, there is no longer a common, noise-free path from the operational amplifier to the output for a simple voltage-sensing connection.
Moving the operational amplifier to a reference node that is referenced to the output may require a second biasing source that is referenced to the reference node associated with the power supplied to the operational amplifier. This requirement complicates both the referencing or grounding requirements and the bias supply requirements, as well as increases the costs associated with such a power converter.
Accordingly, what is needed in the art is an efficient and robust way to transform a voltage signal associated with one reference node of an electronic circuit into a voltage signal associated with another reference node of the electronic circuit.
To address the above-discussed deficiencies of the prior art, the present invention provides a voltage reference translation system for use with an electronic circuit having first and second reference nodes. In one embodiment, the voltage reference translation system includes first and second inductors coupled to a common magnetic core and interposed between the first and second reference nodes. Additionally, the voltage reference translation system includes a conversion path coupled through a portion of the common magnetic core configured to substantially convert a signal associated with the first reference node into a signal associated with the second reference node.
In an alternative embodiment, a voltage reference translation system for use with an electronic circuit having first and second reference nodes includes an inductor coupled to a magnetic core and interposed between the first and second reference nodes. Additionally, the voltage reference translation system includes a conversion path coupled through a portion of the magnetic core configured to substantially convert a signal associated with the first reference node into a signal associated with the second reference node.
In another aspect, the present invention provides a method of converting signals between first and second reference nodes associated with an electronic circuit. The method includes providing first and second inductors coupled to a common magnetic core between the first and second reference nodes. The method also includes converting a signal associated with the first reference node into a signal associated with the second reference node with a conversion path coupled through a portion of the common magnetic core.
In yet another alternative embodiment, the present invention provides a method of converting signals between first and second reference nodes associated with an electronic circuit. The method includes providing an inductor coupled to a magnetic core between the first and second reference nodes and converting a signal associated with the first reference node into a signal associated with the second reference node with a conversion path coupled through a portion of the magnetic core.
The present invention also provides, in yet another aspect, an electronic circuit including a transformer coupled to an input of the electronic circuit, an output capacitor coupled to an output of the electronic circuit and first and second reference nodes. The electronic circuit also includes a voltage reference translation system having first and second inductors coupled to a common magnetic core and interposed between the first and second reference nodes. The voltage reference translation system also has a conversion path coupled through a portion of the common magnetic core that substantially converts a signal associated with the first reference node into a signal associated with the second reference node.
The foregoing has outlined, rather broadly, preferred and alternative features of the present invention so that those skilled in the art may better understand the detailed description of the invention that follows. Additional features of the invention will be described hereinafter that form the subject of the claims of the invention. Those skilled in the art should appreciate that they can readily use the disclosed conception and specific embodiment as a basis for designing or modifying other structures for carrying out the same purposes of the present invention. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the invention in its broadest form.